Hello Mohammed,
The item preview feature is meant to be quick short information, however I released update to add a separate
template for the buy now items no problem.
Please download the latest version is been uploading now, update the the files ViewItem.pm and there is
a new template called ItemPreviewBuy.html in the themes/default/view you need to update it also
and you will be able to see separate templates for auction or buy it now items only.
Thank you
Mewsoft Support www.mewsoft.com